The child immunization schedule has been carefully designed so children receive each vaccine when they are the most vulnerable and when the vaccinations produce the best response from their immune systems. Delaying vaccines means delaying protection from diseases. However, for highly mobile families, such as those in the military, following a vaccination schedule can be difficult.

Military children were also more likely to be incompletely vaccinated. Children who were military dependents who were non-Hispanic black or who were younger than 30 months of age were at a significantly higher risk of not being up to date.

The study authors conclude the high mobility rate of military families, a lack of military–wide childhood immunization registration, and incomplete documentation of vaccines could contribute to the lower vaccination rates among this group of children.